/*
 * Sonatype Nexus (TM) Open Source Version
 * Copyright (c) 2008-present Sonatype, Inc.
 * All rights reserved. Includes the third-party code listed at http://links.sonatype.com/products/nexus/oss/attributions.
 *
 * This program and the accompanying materials are made available under the terms of the Eclipse Public License Version 1.0,
 * which accompanies this distribution and is available at http://www.eclipse.org/legal/epl-v10.html.
 *
 * Sonatype Nexus (TM) Professional Version is available from Sonatype, Inc. "Sonatype" and "Sonatype Nexus" are trademarks
 * of Sonatype, Inc. Apache Maven is a trademark of the Apache Software Foundation. M2eclipse is a trademark of the
 * Eclipse Foundation. All other trademarks are the property of their respective owners.
 */
package org.sonatype.nexus.common.app;

import static com.google.common.base.Preconditions.checkState;

/**
 * Some kind of writable component that can be temporarily frozen.
 *
 * @since 3.21
 */
public interface Freezable
{
  /**
   * Freezes the component, disallowing writes.
   */
  void freeze();

  /**
   * Unfreezes the component, allowing writes.
   */
  void unfreeze();

  /**
   * Is this component currently frozen?
   */
  boolean isFrozen();

  /**
   * Ensures that this component is currently readable.
   */
  default void checkReadable() {
    // assume readable by default
  }

  /**
   * Ensures that this component is currently writable.
   */
  default void checkWritable() {
    checkState(!isFrozen());
  }
}
